As a young boy, David Mendez heard the story about his cousin Angel's heroic sacrifice in Vietnam, of how the 20-year-old Marine Sergeant ran through enemy fire and died rescuing his wounded commanding officer.

That sacrifice, he said, helped inspire him to join the U.S. Army himself, to follow in Angel's footsteps.

Now, generations of Staten Islanders will have a constant reminder of the sergeant's heroism -- yesterday, the post office at 45 Bay St. in St. George was officially renamed and dedicated as the "Sergeant Angel Mendez Post Office."

"His service was truly an example and the epitome of character, courage, leadership, strength and perseverance. This is Angel's legacy," said David Mendez, a patrol sergeant with the Collier County Sheriff's Office in Florida.

More than 150 people gathered outside the post office yesterday morning, the sun shining as elected officials, Marine Corps veterans and Mendez's family paid tribute.

The bill to honor Angel Mendez was shepherded through the House of Representatives by Rep. Michael Grimm, and recently signed into law by President Obama.

A former resident of Mount Loretto in Pleasant Plains, Mendez volunteered for the Marine Corps in 1964.

On March 16, 1967, Mendez -- a rifleman with Company F, Second Battalion, Seventh Marines, First Marine Division -- volunteered to lead a squad going to the aid of Marines pinned down by machine-gun and automatic weapons fire as Operation DeSoto unfolded in the Duc Pho District, Quang Ngai Province, South Vietnam.

He was told to stay put, but defied his orders and ran 60 meters across an open rice paddy to carry his wounded commander toward friendly lines. He died shielding the commander's body.

That commander, Ronald D. Castille, is now the chief justice of the Pennsylvania Supreme Court.

"He didn't think about his own safety. He didn't think about the politics of the war, why he was there. He knew why he was there, because his country called on him. Period," said Grimm, who is a Marine Corps veteran.

Grimm also read from a letter written by Castille, who said he couldn't attend because he was presiding over the court.

"That I am able to be where I am this day, and holding the position that I serve in as chief justice is due to Angel Mendez, for Angel is the Marine who braved enemy fire in order to rescue me from the battlefield after my combat injuries," Castille wrote.

Mendez's sister, Marie Wach, said the event brought with it the same feeling of excitement as the birth of a child, or a wedding day.

"I think he's smiling down," she said. "He was a humble person. I don't think he'd expect anyone to give him this honor.

Mendez's brother, Ismael, an ex-paratrooper from Yonkers, said he was left "speechless" with pride and emotion during the ceremony.

"It's just an honor for the family," he said.

Mendez was awarded the Navy Cross, and Dennis Tobin, senior vice commandant of the Marine Corps League in Sunnyside, said he'll work tirelessly to see he receives the Medal of Honor, the country's top award for valor against an enemy.

"I will pursue this fight for the Medal of Honor as long as I have the strength," he said.